Improvement in interlocked conical bolts for safes



UNITED STATES PATENT OFFICE.

JOHN FARREL, OF NEW YORK, N. Y.

IMPROVEMENT IN INTERLOCKED CONICAL BbLTS FOR SAFES.

Specification forming part of Letters Patent No. 120,577, dated November 7, 1871.

To all whom it may concern:

Be it known that I, J OHN FARREL, of New York city, have invented an Improvement in Interlocked Conical Bolts for Safes; and the following is a specification. thereof, reference being had to the accompanying drawing.

Said invention relates to the conical screwbolts used in the construction of burglar-proof safes for securing or tying together the several laminae of metal of which the outer wall is composed.

In the attempt to gain access clandestinely to the interior of a safe the walls whereof are con structed and secured as aforesaid, it is an aim to remove the conical bolt or bolts by seizing the butt thereof, lying next the exterior of the safe, with an instrument adapted for the purpose, and then, by applying a powerful leverage, such as jack-screws, to assist, draw the bolts outward, thus leaving a clear opening into the safe. It is the object of this improvement to provide against such withdrawal of the bolts and nullify all attempts to enter the safe in that way.

Referring to the annexed drawing, Figure 1 represents a conical screw-bolt, A, in side view, and the dotted lines indicate the various thicknesses of metal composing the outer wall. Part of the invention consists in forming grooves or notches, one or more, in the side of the bolt, near the butt thereof, as seen atB B. These grooves have two purposes: When located near the outer lamina of metal 1, which is usually wroughtiron, if, by cutting away the metal, the bolt can be seized by the butt end, the power applied to withdraw it would result in parting the bolt; but such result would leave the holding qualities thereof practically unimpaired, inasmuch as the remainder would be found snugly embedded in the lamina 2, of hard steel next adjacent, unimpressible with any ordinary, tools. Another ob jeet of the grooves is to provide for locking the bolt fast in the wall. of metal by means of inter locking-bars G or collars D. These are inserted in the grooves or notches laterally as to the axis of the bolt, and fitted to conform to the bottom of the groove, which is shaped to correspond with the diverging lines of the exterior of the bolt. These bars will effectually prevent the bolt from being withdrawn by any appliance that may be brought to bear on the outside of the safe; and in the event of the parting of the bolt, whatever part remains still holds firmly the then outer layer of metal by virtue of the shape of the bottom of the groove, as aforesaid.

The collars or bars 0 D may be inserted during the process ofbuilding the safe or afterward, andin thelatter case may take the form of latches, to yield when the bolt is inserted, and, when it is driven or screwed to its place, fall into the grooves provided therefor. And many other modifications will occur to the expert artisan, all embodying the same invention.

I claim- 1. A screw-bolt, to be used in the construction of safes having the narrow peripheral grooves shown near the'butt thereof, when the body of the bolt is of tapering or conical shape, in order to maintain its holding capacity if parted, substantially as described.

2. In combination with the grooved conical screw-bolt the interlocking-bars or collars, substantially as and for the purpose specified.

JOHN FARREL.

Witnesses:

EARLE B. SMITH,

FRANK O. HERRING. (128) 

